In modern industrial automation, the performance of motion control systems often depends on the perfect coupling between motors and reducers. Bonfiglioli's BMS (Bonfiglioli Motion Solution) series precision planetary servo reduction motors are highly integrated products designed to meet this demand. It integrates a low backlash planetary gearbox with a high-performance permanent magnet synchronous servo motor, providing a compact and efficient driving solution for fields such as packaging, material handling, automatic warehousing, and textile machinery.
Chapter 1: Core Values and Technical Positioning of BMS Series
The BMS series is not just a simple combination of motor and gearbox, but a deeply optimized mechatronics solution.
1.1 Integration advantages
Compared to traditional split type motors and reducers, the integrated design of BMS brings significant competitive advantages:
Compact profile size: eliminates the need for adapter flanges and couplings between the motor shaft and gearbox input shaft, resulting in a significant reduction in overall length.
Optimized performance matching: Based on Bonfly's dual expertise in the fields of gearboxes and motors, the motor output characteristics of BMS have been accurately matched with the torque carrying capacity of the gearbox, avoiding performance redundancy or insufficiency caused by improper selection.
Higher rigidity and lifespan: The integrated shell design enhances overall rigidity, and thanks to optimized bearing layout, the BMS series can withstand higher radial and axial loads, resulting in longer bearing lifespan.
1.2 Application Scenarios
This series is designed for applications with high dynamic response and high-precision positioning. Whether it's stacker cranes in automated warehouses, cutting mechanisms on packaging production lines, or rotating axes around robots, BMS can provide precise power transmission. Its standard backlash is as low as 5 arcmin (single-stage), while the optional low backlash version can be controlled within 3 arcmin, which is a key physical indicator to ensure positioning accuracy.
Chapter 2: Selection Calculation: From Application Parameters to Specific Models
The correct selection is the cornerstone of stable equipment operation. Bangfeili provides a rigorous selection methodology, the core of which is to determine the most suitable model based on the torque speed curve of the load.
2.1 Analysis and Calculation of Operating Conditions
Firstly, it is necessary to analyze the duty cycle of the application. For example, if the device includes long-term constant speed operation and short-term acceleration and deceleration within a cycle, it is necessary to calculate the torque requirements for different stages separately M two(i) M 2(i).
According to the selection process diagram in the document (Chapter 12), we need to first calculate the cycle duration factor ED%
ED%=t one+t two+⋯+tn
Total cycle time×one hundred%
ED%= Total cycle time
t one+t two+⋯+t n ×100%
S1 working system (continuous operation): If ED% greater than 60% or a single run time that is too long is usually considered a continuous working system.
S5 working system (intermittent operation): If ED% If the ED% is less than 60% and the single operation time is short, it is considered as an intermittent working system.
2.2 Verification of Peak Torque and Equivalent Torque
Peak torque(M two PEAK M 2 PEAK)Must be less than or equal to the maximum acceleration torque allowed by the gearbox M two
This is the first line of defense to protect gears from impact damage.
Equivalent torque(M two EQU M 2 EQU)For variable load conditions, it is necessary to calculate the root mean square torque. The formula is as follows:
M two EQU=M two(one) two⋅t one+M two(two)two⋅t two+…t one+t two+…
M 2 EQU= t one+t two+…M 2(1)two⋅t one+M 2(2) two⋅t two+…
This value must be less than the rated torque of the gearbox
M n two M n2 To ensure that overheating does not occur during long-term operation.
2.3 Verification of output speed
Confirm the maximum speed of the application n max
Do not exceed the maximum allowable input speed (considering speed ratio) or output speed of the gearbox. If the speed is too high, a larger gear ratio (i) or a larger specification gearbox should be selected.

Chapter 3: In depth Interpretation of Key Performance Parameters
Understanding several key parameters is crucial for selection when consulting BMS performance data sheets.
3.1 "Overspeed Variants"
The BMS series offers three "overspeed" variants for the same motor: BASE, MEDIUM, and HIGH (B, M, H) (Chapter 18).
Core logic: These three variants are essentially different in the winding characteristics of the motor.
B-type (Base): Optimized for conventional speed applications, with low current consumption and high cost-effectiveness.